Sole



H. K. HITCHCOCK.

SOLE.

APPLICATION FILED DEC. II, !917.

Patented May 18, 1920.

Ooo

O O O INVENTOH.

to a magnified degree.

EALBERT K. HITCHCOCK, OF PITTSBURGH, PENNSYLVANIA SOLE.

Speccation of etters Patent.

Patented May 18, 1920.

Application filed December 17, 1917. Serial No. 207,&13.

To all 'whom 't may concem:

Be it known that I, HALBERT K. HITCH- COCK, a citizen of the United States, residing at 'Pittsburgh, in the County of Allegheny and State of Pennsylvana, have invented certain new and useful Improvements in Soles, of which the following is a specificationl The invention relates to soles for shoes and boots, and has for its primary objects the provision of a sole of the yeldng composition type which shall have all of the advantages incident to a sole of such type and in addition shall have the advantages of the relatively Stifler harder leather sole Certain embodiments of the invention are illustrated in the accompanying drawings, wherein- Figure l is a plan View of the improved sole; Fig. 2 is a longitudinal section through the sole of Fig. l; Fig. 3 is a transverse section on an enlarged scale on the line III* III of Fig. l; Fig. 4: is a plan View of a modified form of stiffening plate; and Fig. 5 is a plan View of another modification.

In its preferred embodiment the sole comprises three members, a lower resilient wearing element l, and upper element 2, and

an interposed stiening member 3 provided with perforations 4. The wearing element or sheet 1 may be composed of any one of a large number of sole compositions now employed in place of leather. In general these compositions contain a greater or less proportion of rubber, .and are relatively flexible and resilient. In some cases the material is termed rubber but is in fact a composition of rubber and some filler adapted to make the material cheaper and at the same time more durable.

The stiffening plate 3 is preferably made of a thin sheet of metal such as steel or bronze orthard rubber, although it might be made of other materials, the requirement being that the plate or layer should be sut-i ficienty stiff to divide the load of the foot above over a relatively large portion of the sole below and fiexible enough to bend easily in the various planes necessary to make walking easy.

When a springingplate of metal or hard rubber is used'the properties of stifiness in a direction crosswise .of the sole is obtained by the thickness of the plate and 'the strength of the material, while the ease with which it bends in the ordinary process of ,walking is easily controlled by the nature of the perforations 4. When it is desired to make the sole more flexible in this direction the number of the perforations are increased and they are laid out at right .angles to the middle axis of the sole taken lengthwise. As this angle is made more acute, as indicated at 4' in F ig. 4, the res'istance to bending in this plane is greater so that it is possible to get a combination that will exactly fit every requirement. This can also be done by the proper arrangement of round perforations, as indicated at in Fig. 5, as will be readily understood.

By reinforcing that part of the stiffening member at any point, as at the instep, the foot can also be additionally supported and a condition obtained that will give to each part of the sole just that stifness that is most desirable to meet any condition of service. i Such stitening in the form of a depression in the metal plate is shown at 5 in Figs. 1 and 2.-

The upper element or sheet 2 is preferably also composed of a composition containing some rubber, although this is not necessarily the case. The requirement here is for a material which will gradually conform itself to the shape of the bottom of the foot,

so as to distribute the pressure evenly over a large section of the sole of the foot, therefore the material should not be too resilent. A rubber composition containing a relatively large amount of filler will meet the requirement. As indicated in Figs. 2 and 3,

the upper surface of the' element 2 is approximately shaped to the contour of the bottom of the foot and in use the surface is deformed still more, gradually assunng the exact contour of the bottom of the foot.

The element 2 is secured to the element 1 by cementing or vulcanizing' the two parts together.

The sole as above described combines the advantages of the composition'and leather soles heretofore made, and involves certainadvantages over both. The rubber, orcomposition sole, has the advantage over leather in that it is more flexible, and resilient, gives a better grip, and is water-proof, but has the disadvantage incident to its lack of stiffness,

.that the foot is fatigued where the walking is rough, since' the pressure on the sole due to irregularities l-;slocalized on the ;sole of the foot. The sole isf'also caused to move relatively to the sole of the foot producing a heating efl'ect, and the resilient character of the sole prevents its setting to the contour of the bottom of the foot as is the case witli a leather shoe after long use.

On the other hand the leather sole is' relatively stifl and uncomfortable when first worn and lacks the advantages of the rubber or composition sole in the matter of grip and the exclusion of water. Furthermore, although its upper surface does even- I tually set to the foot giving the large area 'that of 'leather and prevents an of contact necessary for comfort, such efiect is often only Secured after a long period of wear so that the sole is comfortable for only a portion of the period of wea r.. The improved sole herein set forth avoids'the disadvantages of both the leather and composition soles. The` lower wearing element 1 has the advantages of grip, flexibleness and exclusion of water characteristic of composition. soles, while the stiffening plate 3 gives the sole a stifiness correspo'diug to pressn'e upon the lower side of the sole om being localized upon the sole'of the foot. At the same time the plate can be made of such lightness and flexibility that the necessary bending incident to walking is not interfered with. The upper element 2, which is in a sense somewhat plastic, very quickly tially inte The contact relatively stili reinforcing material therefor, and an upuper element also of rubber composition similar to that of the wearing element but containing'more filler' and relatively less resilient and adaptedjto set to the shape of the foot, the said wearing element and upper element having their oppo'sing surfaces .cured togetherso as to form a substantilly integral structure. v v

2. sole comprising a resilient wearing element of rubber composition andan' upper element also of rubber composition similar to that ocf the wearing .element but contain'- ng more filler and relatively less resilient and adapted to set to the shape of the foot,

the wearing element and upper element being cured togetherso as to form a substanalstructure.

ALBERT K. HITCHCOCK. 

